C8B Gene: Complement C8 Beta Chain
Genetic and Functional Insights into the Complement Component C8B
Gene Information Card
| Symbol | C8B |
|---|---|
| Full Name | Complement C8 Beta Chain |
| Gene Type | Protein coding |
| Chromosomal Location | 1p36.22 |
| NCBI Gene ID | 732 ncbi.nlm.nih.gov/gene/732 |
| Ensembl ID | ENSG00000121858 |
| UniProt ID | P07358 |
| OMIM ID | 120960 |
| HGNC ID | 1353 |
| Aliases | C8B1, complement component 8, beta polypeptide |
Description
The C8B gene encodes the beta subunit of complement component 8 (C8), a constituent of the membrane attack complex (MAC) that mediates cell lysis in the innate immune system. C8 is a heterotrimer composed of alpha, beta, and gamma chains; the beta chain is essential for C8 incorporation into the MAC. Mutations in C8B cause complement component 8 deficiency, predisposing individuals to recurrent Neisseria meningitidis infections.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Complement component 8 deficiency | Loss-of-function mutations in C8B prevent formation of functional MAC, impairing immune defense against Neisseria species. | ClinVar, OMIM |
| Recurrent meningococcal infections | C8B deficiency leads to inability to lyse Neisseria meningitidis, resulting in recurrent infections. | NCBI Gene, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Spleen | 6.8 | Low |
| Blood | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.1 | Hepatocyte cell line |
| K-562 | 3.5 | Myelogenous leukemia line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.165C>A (p.Cys55Ter) | Nonsense | Rare | Loss of function; premature stop codon |
| c.1282C>T (p.Arg428Ter) | Nonsense | Rare | Loss of function; truncated protein |
Mutation functional classification
Loss of Function (LOF)
Most C8B mutations are loss-of-function, leading to complement C8 deficiency.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • complement activation | • membrane attack complex |
| • protein binding | • innate immune response |
| • extracellular region |
Pathways
• Complement cascade (KEGG: hsa04610)
• Staphylococcus aureus infection (KEGG: hsa05150)
Protein Summary
Complement component C8 beta chain is a 64 kDa protein that forms part of the C8 complex. It is synthesized primarily in the liver and circulates in plasma. The beta chain mediates binding of C8 to the C5b-7 complex, initiating MAC assembly. Deficiency results in increased susceptibility to Neisseria infections.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| C8B Knockout HEK293 Cell Line | EDJ-KQ3488 | Human | 732 | Details Get a Quote |
| C8B Knockout HeLa Cell Line | EDJ-KQ52752 | Human | 732 | Details Get a Quote |
| C8B Knockout A-549 Cell Line | EDJ-KQ61222 | Human | 732 | Details Get a Quote |
| C8B Knockout HCT 116 Cell Line | EDJ-KQ69718 | Human | 732 | Details Get a Quote |
